1. Field of the Invention
The present invention relates to signaling systems and more particularly, to signaling systems which provide both audible and visual signaling of particular events.
2. Description of the Prior Art
Most alarm systems currently in use are designed for normal hearing persons and provide audible signaling of emergency conditions such as fire, smoke or other potential dangers. Alarm systems have also been developed for hearing-impaired persons which provide visual signaling of emergency conditions, for example by a repeatedly operated, high intensity strobe lamp. Newly promulgated safety regulations in most jurisdictions require public buildings and other areas which are likely to be occupied by both normal hearing and hearing-impaired persons to be equipped with alarm systems suitable for all occupants. Alarm systems are known which provide both audible and visual signaling of emergency conditions. These dual signaling systems are suitable for new building construction or original installations. However, when the alarm system of an existing building, typically providing only audible signaling, must be upgraded to provide both audible and visual signaling, the present state of the art requires, at the very least, removal of the audible alarm system and replacement with the dual signaling system. Installation of some dual signaling systems also require re-wiring back to the main panel and major changes in the panel itself. This is an obvious economic disadvantage.